<template>
    <!-- 底部 -->
    <div class="my-footer">
      <!-- 全选 -->
      <div class="custom-control custom-checkbox">
        <input type="checkbox" class="custom-control-input" id="footerCheck" v-model="isAll" >
        <label class="custom-control-label" for="footerCheck">全选</label>
      </div>
      <!-- 合计 -->
      <div>
        <span>合计:</span>
        <span class="price">¥ {{allPrice}}</span>
      </div>
      <!-- 按钮 -->
      <button type="button" class="footer-btn btn btn-primary">结算 ({{allCount}})</button>
    </div>
  </template>
  
  <script>
  export default {
    props: {
    arr: Array
  },
    data(){
      return{

      }
    },
    computed:{
     isAll:{
      set(checked){  // val就是关联表单的值(true/false)
      this.$emit('sumFn',checked)
   },
     get(){
       // 查找小选框关联的属性有没有不符合勾选的条件
       // 直接原地false
     return this.arr.every(item =>item.goods_state === true)
   },
     },
     allCount(){
        return this.arr.reduce((sum,obj) =>{
           if( obj.goods_state === true ){
             sum += obj.goods_count
           } 
           return sum
        },0) 
     },
     allPrice(){
       return this.arr.reduce((getSum,obj) =>{
        if(obj.goods_state){
          getSum += obj.goods_count * obj.goods_price
           } 
           return getSum
       },0)
     }
    }
  }
  </script>
  
  <style lang="less" scoped>
  .my-footer {
    position: fixed;
    z-index: 2;
    bottom: 0;
    width: 100%;
    height: 50px;
    border-top: 1px solid #ccc;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 10px;
    background: #fff;
  
    .price {
      color: red;
      font-weight: bold;
      font-size: 15px;
    }
    .footer-btn {
      min-width: 80px;
      height: 30px;
      line-height: 30px;
      border-radius: 25px;
      padding: 0;
    }
  }
  </style>